The given pie chart illustrates the triggers for worldwide land degradation, while the table gives an overview of how these reasons affected North America, Europe and Oceania during 1990.
It is clear from the pie chart that over-grazing is the biggest cause for agricultural production decrease, taking 35 percent of worldwide causes. Furthermore, Oceania has the maximum percentage of degrading land by the mentioned type. The second cause is deforestation, being a bit less compared to the previous one, with 30 percent of causes. In terms of the regions, Europe has this problem as the most noticeable one affecting the region with 9. 8 percent.
In general, the total land degradation in North America reaches only 5 percent while Wurope takes the lead with 23 percent.
In conclusion, there are several causes leading to the decreasing number of land agriculture, especially because of the high percentage of overgrazing and deforestation. The three regions of the worlds have been drastically affected by these aspects during 1990. 
The  
given
 pie chart illustrates the triggers for worldwide  
land
 degradation, while the table gives an overview of how these reasons  
affected
 North America, Europe and Oceania during 1990.
It is  
clear
 from the pie chart that over-grazing is the biggest  
cause
 for agricultural production decrease, taking 35 percent of worldwide  
causes
.  
Furthermore
, Oceania has the maximum percentage of degrading  
land
 by the mentioned type. The second  
cause
 is deforestation, being a bit less compared to the previous one, with 30 percent of  
causes
. In terms of the regions, Europe has this problem as the most noticeable one affecting the region with 9. 8 percent. 
In general
, the total  
land
 degradation in North America reaches  
only
 5 percent while  
Wurope
 takes the lead with 23 percent. 
In conclusion
, there are several  
causes
 leading to the decreasing number of  
land
 agriculture,  
especially
  because
 of the high percentage of overgrazing and deforestation. The three regions of the worlds have been  
drastically
  affected
 by these aspects during 1990.